1. Field of the Invention
The present invention relates to a laser treatment apparatus for irradiating an affected part of a patient with a treatment laser beam to treat the affected part.
2. Description of Related Art
There have been used laser treatment apparatus such as a photocoagulation device for irradiating an affected part of an eye fundus of a patient with a treatment laser beam (hereinafter simply referred to as a treatment beam) to coagulate the affected part by heat for treatment. In irradiation of the treatment beam to the eye fundus, such the apparatus is operated by an operator, who observes the patient""s eye with a slit lamp, to perform sighting (aiming) of the treatment beam to a desired site on the affected part by utilizing an aiming laser beam (hereinafter simply referred to as an aiming beam) made coaxial with the treatment beam. When the aiming beam and the treatment beam are different in color (wavelength), which causes refraction and dispersion differences based on the wavelength differences, the difference may possibly occur in reaching conditions to the eye fundus between the beams of different colors (wavelengths). For preventing this problem, it is preferable to use the aiming beam of the same color as the color of the treatment beam.
In the laser treatment apparatus, normally, a protective filter is interposed in an optical path for observation in the slit lamp in order to cut or intercept the treatment beam reflected by the patient""s eye and others to protect the eyes of an operator during the treatment beam irradiation. Accordingly, if the aiming beam of the same color as that of the treatment beam is used, the aiming beam is also cut or intercepted by the protective filter, so that the aiming beam becomes invisible. As a result, the irradiation site of the aiming beam, namely, of the treatment beam could not be visually recognized by the operator during the treatment beam irradiation.
The present invention has been made in view of the above circumstances and has an object to overcome the above problems and to provide a laser treatment apparatus which enables an operator to recognize an irradiation site with a treatment beam during irradiation even if using an aiming beam having the same color (wavelength) as that of the treatment beam.
Additional objects and advantages of the invention will be set forth in part in the description which follows and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
To achieve the purpose of the invention, there is provided a laser treatment apparatus for irradiating an affected part of a patient with a treatment laser beam to treat the affected part, the apparatus including: treatment laser beam irradiation means for emitting and delivering the treatment laser beam of a wavelength in a visible region to irradiate the affected part; observation means provided with an observation optical system for observing the affected part; a protective filter disposed in an optical path of the observation optical system, for intercepting the treatment beam; first aiming beam irradiation means for emitting and delivering a first aiming beam of about the same wavelength as the wavelength of the treatment beam to irradiate the affected part; second aiming beam irradiation means for emitting and delivering a second aiming beam of a different wavelength in a visible region from the wavelength of the treatment beam to irradiate the affected part; and aiming beam switching means for switching between irradiation of the first aiming beam and irradiation of the second aiming beam.
Preferably, the laser treatment apparatus further includes trigger means for generating a trigger signal to instruct irradiation of the treatment beam, wherein the aiming beam switching means switches between irradiation of the first aiming beam and irradiation of the second aiming beam in accordance with a presence or absence of the trigger signal from the trigger means.
Preferably, the laser treatment apparatus further including filter detection means for detecting whether the protective filter is in the optical path of the observation optical system, wherein the aiming beam switching means switches between irradiation of the first aiming beam and irradiation of the second aiming beam in accordance with a detection result of the filter detection means.
Preferably the laser treatment apparatus further including: trigger means for generating a trigger signal to instruct irradiation of the treatment beam; filter moving means for inserting or retracting the protective filter in or from the optical path of the observation optical system; and control means for controlling the filter moving means in accordance with a presence or absence of the trigger signal from the trigger means.
In the laser treatment apparatus, preferably, the aiming beam switching means switches between irradiation of the first aiming beam and irradiation of the second aiming beam in accordance with a type of an insertion/retraction driving mechanism of the protective filter.
In the laser treatment apparatus, preferably, the first aiming beam irradiation means includes attenuation means for attenuating output power of the treatment laser beam, the treatment laser beam with the attenuated output power being irradiated as the first aiming beam to the affected part.
In the laser treatment apparatus, preferably, the attenuation means includes a filter for attenuating the output power of the treatment beam to 1/100 to 1/1000.
According to another aspect of the present invention, there is provided a laser treatment apparatus for irradiating an affected part of a patient with a treatment laser beam to treat the affected part, the apparatus including: a treatment beam irradiation optical system provided with a first laser source for emitting the treatment laser beam of a wavelength in a visible region, for delivering the treatment beam to irradiate the affected part; an observation optical system for observing the affected part; a protective filter disposed in an optical path of the observation optical system, for intercepting the treatment beam; a first aiming beam irradiation optical system for emitting and delivering a first aiming beam of about the same wavelength as that of the treatment beam to irradiate the affected part; a second aiming beam irradiation optical system provided with a second laser source for emitting a second aiming beam of a different wavelength in the visible region from the wavelength of the treatment beam, for delivering the second aiming beam to irradiate the affected part; and a control unit for switching between irradiation of the first aiming beam and irradiation of the second aiming beam.
In the laser treatment apparatus, preferably, the first aiming beam irradiation optical system includes attenuation means for attenuating output power of the treatment laser beam emitted from the first laser source, and the attenuated treatment laser beam being used as the first aiming beam.
In the laser treatment apparatus, preferably, the attenuation means includes a filter for attenuating the output power of the treatment laser beam to 1/100 to 1/1000.
In the laser treatment apparatus, preferably, the control unit controls the first laser source, the second laser source and the attenuation means individually to switch between irradiation of the first aiming beam and irradiation of the second aiming beam.
Preferably, the laser treatment apparatus further including a trigger switch for generating a trigger signal to instruct irradiation of the treatment laser beam, wherein the control unit switches irradiation of the first aiming beam and irradiation of the second aiming beam in accordance with a presence or absence of the trigger signal.
Preferably, the laser treatment apparatus further including a sensor for detecting whether the protective filter is in the optical path of the observation optical system, wherein the control unit switches between irradiation of the first aiming beam and irradiation of the second aiming beam in accordance with a detection result of the sensor.
Preferably, the laser treatment apparatus further including: a trigger switch for generating a trigger signal to instruct irradiation of the treatment laser beam; and a filter moving unit for inserting/retracting the protective filter in/from the optical path of the observation optical system; wherein the control unit controls the filter moving unit in accordance with a presence or absence of the trigger signal.